Dame Helen Mirren has said it was "a bit of a challenge" working with Ben Wishaw on The Tempest - because most of the time he was represented by a tennis ball.

The actress plays Prospera in the latest film adaptation of the Shakespeare play, while Ben plays Ariel.

Asked what it was like working with him, Dame Helen said: "It was a bit of a challenge, he was a tennis ball on a stick for a lot of the time. But you know that's the way digital effects work and our job as actors is to live in the world of the imagination, so that's what we do for a living. So it wasn't so difficult."

She added: "It was better when he was there though, I must say, when he wasn't a tennis ball. Ben is a much better actor than a tennis ball."

But the actress said the hardest thing about making the film was having to wear layers of clothing in the hot weather.

She said: "Heavy costumes in Hawaii in the heat - there were those kind of challenges, and also demanding language, it's really action of the brain and of the tongue than of the body."